In recent years, consumers have become much more interested in healthy and environmentally-friendly lifestyles and products. Indoor air quality is one particular example of this heightened health and environment consciousness. A wide range of products from HIPPA air filters to radon detectors are now available to help consumers monitor and control the quality of air that is breathed indoors.
Indoor air quality is particularly pertinent to makers of construction and building materials, because indoor air quality can be affected by the level of organic materials such as volatile organic compounds (“VOCs”) that are emitted by construction materials, such as carpets, furniture, finishes, paints, and ceiling tiles.
Engineered wood construction materials used to form the framework and supporting structure of buildings are another example of constructions materials that contribute to indoor VOC emissions. These engineered wood construction materials, are formed from lignocellulosic strands bonded together by adhesive resins. Examples of such engineered wood materials include plywood, particle board and oriented strand board (“OSB”). For example OSB is made from lignocellulosic strands selected from pine, aspen, oak, maple, fir, gums, and possibly other wood species, while the adhesive resin is present in concentration ranges of 2% to 12% on the surface and may include adhesives such as melamine, urea, phenol, and formaldehyde or melamine, urea, and formaldehyde; pMDI resin at application levels of 1% to 6% is used in the core of the material and also added is emulsion or slack wax.
As can be seen from the list of product ingredients above, these engineered wood products contain VOCs which may be released during the lifetime of a building or structure made from the engineered wood products. These VOCs include formaldehyde, methanol, pinene, and other olefins and aldehydes. While adhesive resins are a typical source of VOCs, the wood itself may be a more significant source of VOCs; for example pine is a significant source of the aforementioned pinene emissions. But the specific VOCs and the quantity in which they are emitted will vary with each individual wood species. Some of these compounds are regulated by OSHA as well as the EPA as hazardous air pollutants at high concentration levels. For example, formaldehyde emissions from building materials used for constructing mobile homes are already rather strictly regulated.
Commonly made engineered wood panels such as aspen wood strands bonded with pMDI adhesive generate lower VOC emissions than other types of engineered wood and pass the special certification standards used in the industry to denote “green” products, i.e. products that meet heightened environmental and health standards. However, engineered wood panels made from other raw materials, such as pine strands, typically have higher VOC emissions. These VOC emissions are sufficiently high that pine-containing engineered wood material does not meet the standards for green certification.
Accordingly, there is a need in the art for a pine-containing engineered wood material with significantly reduced VOC emissions so that the material will meet heightened environmental and health standards.